ABSTRACT
Purpose:
To evaluate the visual, topographic, and refractive outcomes of the implantation of asymmetric segments (AS) of the ICRS intracorneal ring in eyes with keratoconus and irregular/asymmetric astigmatism (phenotypes type 2 Duck and 3 Snowman by morphological classification of Fernandez-Vega/Alfonso Keratoconus).
Methods:
Prospective clinical study including 60 patients (60 eyes) with keratoconus who underwent implantation of the Kearing ICRS selected and implanted according to the Mediphacos nomogram (http://kearing.online) with femtosecond laser. Preoperative and postoperative evaluations included uncorrected visual acuity, best corrected visual acuity, refractive astigmatism, spherical equivalent, and topographic astigmatism, Kmax, and coma measured with the Galilei (Ziemer, Port, Switzerland). All parameters were assessed preoperatively and at 3 and 6 months postoperatively.
Results:
Overall mean age was 26.34 ± 8.49 years; 28 (56.7%) were female, 34 eyes had keratoconus of type 2 phenotype and another 26 eyes of type 3 phenotype. At 6 months postoperatively, eyes with type 2 phenotype obtained gains in uncorrected visual acuity and best corrected visual acuity of 0.30 LogMAR and 0.15 LogMAR, respectively; and reductions of 2.45D in topographic astigmatism; 2.30D in Kmax; 0.32μm in coma; 1.63D in refractive astigmatism and 1.88D in spherical equivalent. At 6 months, eyes with type 3 phenotype obtained gains in UDVA and CDVA of 0.50 logMAR and 0.10 LogMAR, respectively; and reductions of 3.00D in topographic astigmatism; 5.20D in Kmax; 0.09μm in coma; 2.00D in refractive astigmatism and 4.25D in spherical equivalent. The results of the comparisons at 3 and 6 months postoperatively were not statistically significant for any of the variables evaluated, which denotes the stability of the procedure in this follow-up time.
Conclusion:
Implantation of the asymmetric Kearing in eyes with keratoconus and asymmetric/irregular astigmatism (type 2 and 3 phenotypes) improved visual, topographic, and refractive parameters with safety and clinical efficacy.
Keywords:
Keratoconus; Astigmatism; Corneal topography; Visual acuity; Asymmetric ring